"If I may jump in here (not a Raymarine moderator), here are the instructions I received when I had problems with my AIS 650. Note that there are two steps to the installation, which differ from the instructions at the download site.
"I'm back here again with a similar but potentially more dangerous issue. We took our first trip this year down to the lower Columbia where a chart is absolutely essential. Other than the screen flicker the unit was frequently…"
"The ST5000 is a control unit, where the Control head and course computer is all in one unit. You will only be able to replace with another ST5000, or upgrade to a complete package, with control head, EV-1, and ACU. What is the model number of…"
"Here are voltage measurements from recent test:At battery - 12.47vAt circuit breaker - 12.36vAt autopilot display head in "standby" - 12.36v steadyAt autopilot display head in "auto" mode -12.29v most of the time…"
"Unfortunately if you have tested the compass and it is working, the issue will be within the X5 course computer and I would have to recommend that the course computer be sent to the below address to be evaluated by a service technician for…"
"The step to press power is missing. Power down, remove chip. While holding the Back button, touch Power and keep holding the Back button. That brings up the reset options (let go). Then press WPT for the reset process to start."
"Thanks, I downloaded and installed the update. The green light came on for a second, not the twenty seconds the download how-to said, then went to solid amber. Hopefully it just went really quick! Thanks for your help